My sister has a MacBook pro and today when she turned it on it did this. She said it has done it 3 times already. Not sure what it causing it or how to fix it.
https://www.youtube.com/watch?v=4S4LggOsSvU&list=UUI_t9EqCdS69uVDXX-UY4sg
https://www.youtube.com/watch?v=4S4LggOsSvU&list=UUI_t9EqCdS69uVDXX-UY4sg